Washer-dryer stops heating during wash; program continues with cold water and E05 is displayed.

Safety first: Disconnect from mains and allow the machine to cool before accessing the heater.

Step-by-step checks:

• Access the heater: On many Proline washer-dryer combos, the wash heater is located at the rear of the tub and accessed from the back panel. Remove the rear cover to expose the heater terminals.
• Visual inspection: Look for signs of burning, melted connectors, or limescale buildup around the heater seal.
• Test the element: Disconnect the heater wires and measure resistance across the heater terminals with a multimeter. A typical reading is 20–30 Ω; infinite resistance indicates a failed element.
• Check the NTC sensor: The temperature sensor is usually mounted in or near the heater bracket. Measure its resistance at room temperature and compare with Proline specifications (commonly 20–30 kΩ at 20°C). If open or shorted, replace the sensor.
• Wiring and PCB: If both heater and sensor test good, inspect wiring back to the control board and check for a stuck or burnt heater relay on the PCB. PCB replacement is usually required if the relay has failed.

When to call a technician: If you are not experienced with electrical testing or PCB work, have a qualified technician diagnose and replace the faulty component.